Still working on the 'new to me' R75/5. I've been debating whether or not to replace the original breather vent to the new reed-valve type. The bike has never run in my possession (yet) and it is in bits and pieces presently. Should I keep the original in place till it runs, or get the updated model vent. There are probably plenty of /5's running around with original breather vents that operate just fine. What do you guys think? Any advantages? If it ain't broke, don't fix it?